This is the competing continuation grant proposal for the General Clinical Research Center at Northwestern University and Northwestern Memorial Hospital. The GCRC has been continuously funded since 1961 and, in the most recent grant renewal, as per diem unit. However, because of current increased activity (over 750 inpatient A days this current year) and proposed sustained and increased activities (to 1200 inpatient A days), we are requesting the creation of a discrete, six bed GCRC. Harry N. Beaty, M.D., Dean of Northwestern University Medical School, continues as overall P.I., and a new cadre of Program and Associate Program Directors, and successful recruitments for the Chairs of Medicine, Neurology, and Community Health and Preventive Medicine, have been added to account for the current and future increased utilization of the CRC. This grant renewal for the CRC has 48 proposals from 83 different investigators, representing both Basic Science (Cell, Molecular, and Structural Biology, Pharmacology) and Clinical Science Departments of the School. The Clinical Departments have expanded to include Medicine, Pediatrics, Neurology, and Urology; five different divisions within medicine and two within Pediatrics are represented by principal investigator and protocol. The breadth of science that will be studied in the CRC is demonstrated by the protocols to be presented at the site visit. This includes, in order of presentation, studies on the genetics of the regulation of vasopressin physiology in familial neurogenic diabetes insipidus by Gary Robertson, M.D., Program Director; studies on the influence of AVP on the renal handling of potassium and hydrogen ion and studies of the influence of altered potassium and altered hydrogen balances on the renal functions of AVP by Daniel Batlle, M.D. and William Schleuter, M.D.; studies on the diurnal rhythmicity of electrophysiologic parameters and their relationship with autonomic nervous system tone, by Alan Kadish, M.D.; studies of adrenomedullary function in lean and obese men and women by James Young, M.D.,; studies of the mechanisms of obesity in the offspring of mothers who were diabetic during pregnancy compared to both the lean offspring of those mothers and obese offspring of nondiabetic pregnancies by Boyd Metzger, M.D., and Bernard Silverman, M.D.; studies of the ability of the aged brain to retain memory stimuli by John Disterhoft, Ph.D. and Bruce Naughton, M.D.; studies of gastrointestinal malabsorption in patients with AIDS by Robert Craig, M.D.; and studies on the metabolism of 1,25 dihydroxyvitamin D in children with hypophosphatemic rickets and their normal siblings by Craig Langman, M.D. and Dorothy Dunlop, PH.D. The studies to be presented and those others proposed in the renewal application represent state of the art scientific investigation into the pathophysiology of human diseases across many disciplines and populations and, if successfully completed, with yield important information for future patient care.